Quote:
Originally Posted by boombox
An interesting (and slightly amusing) diversion!
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It happens... If you're interested in such-like, you might like to get hold of a little book called 'Electric Bells, Alarms and Signalling Sytems', by Herbert G. White (who also wrote a sister book on contemporary 'house' telephone systems).
My copy is dated 1923 and has sections on a.c. and d.c. bells, mains-droppers (
) batteries, annunciators for home, hotel, industrial and alarm use.